If it's available, it will appear on
this page. Currently it's not yet listed in the upcoming beta releases section.
But you could already start preparing if you want to take the beta. Based on my common sense, I would say exam topics will probably focus on the new language features of
Java 7 and Java 8, together with new introduced exam topics in OCP7 and OCP8 (like concurrency, nio 2.0,
jdbc, localization,...). And for those having a pre-OCPJP5 certification (and for others maybe as well), it might be useful to refresh your knowledge about some Java 5 language features like enums and generics.